When Google was launched in 1998, co-founder Sergey Brin tried unsuccessfully to market their PageRank technology. History tells us that nobody at that time was interested in buying or licensing their search technology.

They didn't have to wait too much longer though. They received $100,000 seed funding to get them up and running in 1999. With a $25 million venture capital investment arriving later that year, Google was well and truly in business. Later in 1999 AOL selected Google as a search partner, with Yahoo! following suit in 2000. Google launched their popular Google Toolbar that year and have gained search market share year on year ever since.

Through word of mouth, adoption led to popularity that led to a critical user mass. One of the deciding features of Google that gave it an advantage over the competition was the introduction of PageRank, which graded the value of a page based on the number and quality of links pointing at it. Up until the end of 2003 organic searches had been considered exceptionally easy to manipulate; all you had to do was buy a few powerful links and place the words you wanted to rank in the link anchor text. By integrating PageRank as one of the new algorithmic signals, Google made a decisive move in the battle to stay ahead of the search game.

In October 2007, Google announced that they were going to penalize known link sellers, and then manually edit the toolbar PageRank scores of some well-known blogs and other large sites. These PageRank edits did not change either search engine rankings or traffic flows. The PageRank update was considered entirely aesthetic by many and in the eyes (and blogs) of some only went to demote PageRank's viability as a site's global authority score.

PageRank is only one of numerous methods Google uses to determine a page's relevance or importance. Whatever the significance of PageRank as a component of the overall algorithm, the fact that it at least attempts to reflect site authority and quality can only be a good thing and is reason enough to give it due respect.

When a user enters a query into the Google search engine, Google searches the index for matching pages and returns the considered the most relevant to the user. Relevance is determined by over 200 factors, one of which is the PageRank for a given page. As Google compiles its index, it calculates a number it calls PageRank for each page it finds. This was the key invention of Google's founders, Larry Page and Sergey Brin. PageRank is a link analysis algorithm that tallies how many times other sites link to a given page and assigns a numerical weighting to each element of those links with the purpose of 'measuring' its relative importance.

Whilst overall ranking popularity considers site age, backlink relevancy and backlink duration, PageRank doesn't. Neither is content taken into account when PageRank is calculated, disassociated in that respect from 'on-page' SEO. Topical relevance is measured with link context and on-page factors such as keyword density, title tag, meta data.

Each inbound link is important to the overall total, except banned sites, which don't count. However, not all links are equal and Google strives tirelessly to deliver relevance by identifying spam links and other Black Hat practices that negatively impact search results. Despite Google's massive popularity, with 60% of the U.S market constituting about 7 billion searches a month, millions of times a day users click away from Google, frustrated at not being able to find the specific information they require, be it a hotel, a recipe or airline booking details. It's this disappointing gap between what users want and what is delivered to them that PageRank and the rest of the Google 'signals' that go to make up their algorithm are designed to resolve.

When considering PageRank in the context of SEO, there are a number of issues to take into account. Whilst a high PageRank is preferable, not being an eight, nine or ten doesn't mean that your site won't be enjoy high rankings or traffic or that your business objectives will be unfulfilled.

Top 10 Google Myths Revealed states, 'While pages with a higher PageRank do tend to rank better, it is perfectly normal for a site to appear higher in the results listings even though it has a lower PageRank than competing pages. Google examines the context of your incoming links, and only those links that relate to the specific keyword being searched on will help you achieve a higher ranking for that keyword."

In other words it's not necessarily wise to chase high PageRanks at the expense of everything else. Don't compromise your overall SEO strategy for the sake of PageRank.

Here's some more information that might offer additional PageRank insight in an SEO context.

• Frequent content updates don't improve PageRank automatically. Content is not part of the PR calculation.
• High PageRank doesn't necessarily equate to high search ranking.
• Directory listings such as DMOZ and Yahoo! don't improve PageRank automatically.
• Academic .edu and .gov-sites don't improve PageRank automatically.
• PageRank is determined for each page individually so sub-directories don't necessarily have a lower PageRank than root-directories.
• Pages which extract information from Wikipedia might improve PageRank.
• Due to comment spam links marked with no follow-attribute don't contribute to Google PageRank.
• Well anchored and internally authoritative linking has an impact on PageRank.
• Related high ranked websites carry more weight. However, a page with high PageRank may actually pass less weight if it has more links as the weight becomes dissipated.
• Links from and to high quality related sites have an impact on PageRank.
• Multiple votes to one link from the same page cost as much as a single vote.

Professional and effective SEO is a holistic process, with PageRank reflecting one small and indefinably important thread. For information on how SEO Consult can apply our experience and expertise to effectively incorporate PageRank as part of your overall Internet strategy, contact us today.